Joscha Hoche
Julius-Maximilians Universität Würzburg
Emil-Fischer-Straße 42
97074 Würzburg
Thesis title: Simulation of Photoinduced Energy Transfer and Internal Conversion in pyrene-BODIPY Conjugates
Thesis title: Nichtadiabatische Dynamik der Exzimerbildung
12. | Einsele, Richard; Hoche, Joscha; Mitric, Roland Long-range Corrected Fragment Molecular Orbital Density-FunctionalTight-binding Method for Excited States in Large Molecular Systems Journal Article J. Chem. Phys., 158 , pp. 044121, 2023. @article{Einsele2022, title = {Long-range Corrected Fragment Molecular Orbital Density-FunctionalTight-binding Method for Excited States in Large Molecular Systems}, author = {Richard Einsele and Joscha Hoche and Roland Mitric}, doi = {10.1063/5.0136844}, year = {2023}, date = {2023-01-27}, journal = {J. Chem. Phys.}, volume = {158}, pages = {044121}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
11. | Titov, E; Kopp, T; Hoche, J; Humeniuk, A; Mitric, R (De)localization dynamics of molecular excitons: comparison of mixed quantum-classical and fully quantum treatments Journal Article Phys. Chem. Chem. Phys., 24 , pp. 12136-12148, 2022. @article{Titov2022, title = {(De)localization dynamics of molecular excitons: comparison of mixed quantum-classical and fully quantum treatments}, author = {E. Titov and T. Kopp and J. Hoche and A. Humeniuk and R. Mitric}, doi = {10.1039/d2cp00586g}, year = {2022}, date = {2022-05-25}, journal = {Phys. Chem. Chem. Phys.}, volume = {24}, pages = {12136-12148}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
10. | Patalag, L J; Hoche, J; Mitric, R; Werz, D B; Feringa, B L Transforming Dyes Into Fluorophores: Exciton‐Induced Emission with Chain‐like Oligo‐BODIPY Superstructures Journal Article Angew. Chem. , 61 , pp. e202116834, 2022. @article{hoche_2022_a, title = {Transforming Dyes Into Fluorophores: Exciton‐Induced Emission with Chain‐like Oligo‐BODIPY Superstructures}, author = {L. J. Patalag and J. Hoche and R. Mitric and D. B. Werz and B. L. Feringa}, doi = {10.1002/ange.202116834}, year = {2022}, date = {2022-03-04}, journal = {Angew. Chem. }, volume = {61}, pages = {e202116834}, abstract = {Herein we present a systematic study demonstrating to which extent exciton formation can amplify fluorescence based on a series of ethylene-bridged oligo-BODIPYs. A set of non- and weakly fluorescent BODIPY motifs was selected and transformed into discrete, chain-like oligomers by linkage via a flexible ethylene tether. The prepared superstructures constitute excitonically active entities with non-conjugated, Coulomb-coupled oscillators. The non-radiative deactivation channels of Internal Conversion (IC), also combined with an upstream reductive Photoelectron Transfer (rPET) and Intersystem Crossing (ISC) were addressed at the monomeric state and the evolution of fluorescence and (non-)radiative decay rates studied along the oligomeric series. We demonstrate that a “masked” fluorescence can be fully reactivated irrespective of the imposed conformational rigidity. This work challenges the paradigm that a collective fluorescence enhancement is limited to sterically induced motional restrictions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Herein we present a systematic study demonstrating to which extent exciton formation can amplify fluorescence based on a series of ethylene-bridged oligo-BODIPYs. A set of non- and weakly fluorescent BODIPY motifs was selected and transformed into discrete, chain-like oligomers by linkage via a flexible ethylene tether. The prepared superstructures constitute excitonically active entities with non-conjugated, Coulomb-coupled oscillators. The non-radiative deactivation channels of Internal Conversion (IC), also combined with an upstream reductive Photoelectron Transfer (rPET) and Intersystem Crossing (ISC) were addressed at the monomeric state and the evolution of fluorescence and (non-)radiative decay rates studied along the oligomeric series. We demonstrate that a “masked” fluorescence can be fully reactivated irrespective of the imposed conformational rigidity. This work challenges the paradigm that a collective fluorescence enhancement is limited to sterically induced motional restrictions. |
9. | Schmitt, Hans-Christian; Fischer, Ingo; Ji, Lei; Merz, Julia; Marder, Todd B; Hoche, Joscha; Röhr, Merle I S; Mitric, Roland Isolated 2-hydroxypyrene and its dimer: a frequency- and time-resolved spectroscopic study Journal Article New J. Chem. , 45 , pp. 14949-14956, 2021. @article{hoche_2020_06_njchem, title = {Isolated 2-hydroxypyrene and its dimer: a frequency- and time-resolved spectroscopic study}, author = {Hans-Christian Schmitt and Ingo Fischer and Lei Ji and Julia Merz and Todd B. Marder and Joscha Hoche and Merle I. S. Röhr and Roland Mitric}, url = {https://pubs.rsc.org/en/content/articlelanding/2020/nj/d0nj02391d#!divAbstract}, doi = {10.1039/D0NJ02391D}, year = {2021}, date = {2021-09-07}, journal = {New J. Chem. }, volume = {45}, pages = {14949-14956}, abstract = {We investigated isolated 2-hydroxypyrene and its dimer in the gas phase by time- and frequency-resolved photoionisation with picosecond time-resolution. The experiments are supported by simulations that include an extensive conformational search based on the machine learning ANI-1ccx neural network potential combined with automatic structure classification using a data clustering algorithm. Vibrationally resolved spectra of the S1 ← S0 and S2 ← S0 transitions are reported which are in very good agreement with the simulated spectra at the TDDFT level. As expected from the molecular orbitals involved in the transitions, the red-shifts of the transitions are more pronounced for the S1 state compared to those of unsubstituted pyrene. While a ns-lifetime is observed for the S1 state, the lifetime decreases to 3 ps or less for the origin of the S2 state, indicating a strong interaction between the two states. For the dimer, a slightly V-shaped structure was computed, and intermolecular interactions are dominated by dispersion rather than hydrogen-bonding. The highest oscillator strength was computed for the transition to the S4 state, which deactivates within 4 ps to a lower-lying excited state.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigated isolated 2-hydroxypyrene and its dimer in the gas phase by time- and frequency-resolved photoionisation with picosecond time-resolution. The experiments are supported by simulations that include an extensive conformational search based on the machine learning ANI-1ccx neural network potential combined with automatic structure classification using a data clustering algorithm. Vibrationally resolved spectra of the S1 ← S0 and S2 ← S0 transitions are reported which are in very good agreement with the simulated spectra at the TDDFT level. As expected from the molecular orbitals involved in the transitions, the red-shifts of the transitions are more pronounced for the S1 state compared to those of unsubstituted pyrene. While a ns-lifetime is observed for the S1 state, the lifetime decreases to 3 ps or less for the origin of the S2 state, indicating a strong interaction between the two states. For the dimer, a slightly V-shaped structure was computed, and intermolecular interactions are dominated by dispersion rather than hydrogen-bonding. The highest oscillator strength was computed for the transition to the S4 state, which deactivates within 4 ps to a lower-lying excited state. |
8. | Hoche, J; Flock, M; Miao, X; Philipp, L N; Wenzel, M; Fischer, I; Mitric, R Excimer formation dynamics in the isolated tetracene dimer Journal Article Chem. Sci., 12 , pp. 11965-11975 , 2021. @article{hochej_tetracene_2021, title = {Excimer formation dynamics in the isolated tetracene dimer}, author = {J. Hoche and M. Flock and X. Miao and L. N. Philipp and M. Wenzel and I. Fischer and R. Mitric}, doi = {10.1039/D1SC03214C}, year = {2021}, date = {2021-08-03}, journal = {Chem. Sci.}, volume = {12}, pages = {11965-11975 }, keywords = {}, pubstate = {published}, tppubtype = {article} } |
7. | Patalag, L J; Hoche, J; Holzapfel, M; Schmiedel, A; Mitric, R; Lambert, C; Werz, D B Ultrafast Resonance Energy Transfer in Ethylene-Bridged BODIPY Heterooligomers: From Frenkel to Förster Coupling Limit Journal Article J. Am. Chem. Soc., 143 , pp. 7414-7425, 2021. @article{hoche_2021, title = {Ultrafast Resonance Energy Transfer in Ethylene-Bridged BODIPY Heterooligomers: From Frenkel to Förster Coupling Limit}, author = {L. J. Patalag and J. Hoche and M. Holzapfel and A. Schmiedel and R. Mitric and C. Lambert and D. B. Werz}, url = {https://pubs.acs.org/doi/10.1021/jacs.1c01279}, doi = {10.1021/jacs.1c01279}, year = {2021}, date = {2021-05-06}, journal = {J. Am. Chem. Soc.}, volume = {143}, pages = {7414-7425}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
6. | Lambert, C; Hoche, J; Schreck, M H; Holzapfel, M; Schmiedel, A; Selby, J; Turkin, A; Mitric, R Ultrafast Energy Transfer Dynamics in a Squaraine Heterotriad Journal Article J. Phys. Chem. A, 125 (12), pp. 2504-2511, 2021. @article{hoche_2021b, title = {Ultrafast Energy Transfer Dynamics in a Squaraine Heterotriad}, author = {C. Lambert and J. Hoche and M. H. Schreck and M. Holzapfel and A. Schmiedel and J. Selby and A. Turkin and R. Mitric}, url = {https://pubs.acs.org/doi/abs/10.1021/acs.jpca.1c00349}, doi = {10.1021/acs.jpca.1c00349}, year = {2021}, date = {2021-03-19}, journal = {J. Phys. Chem. A}, volume = {125}, number = {12}, pages = {2504-2511}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
5. | Humeniuk, Alexander; Bužančić, Margarita; Hoche, Joscha; Cerezo, Javier; Mitrić, Roland; Santoro, Fabrizio; Bonačić-Koutecký, Vlasta J. Chem. Phys., 152 , pp. 054107, 2020. @article{humeniuk_2020a, title = {Predicting fluorescence quantum yields for molecules in solution: A critical assessment of the harmonic approximation and the choice of the lineshape function}, author = {Alexander Humeniuk and Margarita Bužančić and Joscha Hoche and Javier Cerezo and Roland Mitrić and Fabrizio Santoro and Vlasta Bonačić-Koutecký}, url = {https://aip.scitation.org/doi/full/10.1063/1.5143212}, doi = {10.1063/1.5143212}, year = {2020}, date = {2020-02-05}, journal = {J. Chem. Phys.}, volume = {152}, pages = {054107}, abstract = {For the rational design of new fluorophores, reliable predictions of fluorescence quantum yields from first principles would be of great help. However, efficient computational approaches for predicting transition rates usually assume that the vibrational structure is harmonic. While the harmonic approximation has been used successfully to predict vibrationally resolved spectra and radiative rates, its reliability for non- radiative rates is much more questionable. Since non-adiabatic transitions convert large amounts of electronic energy into vibrational energy, the highly excited final vibrational states deviate greatly from harmonic oscillator eigenfunctions. We employ a time-dependent formalism to compute radiative and non-radiative rates for transitions and study the dependence on model parameters. For several coumarin dyes, we compare different adiabatic and vertical harmonic models (AS, ASF, AH, VG, VGF, and VH), in order to dissect the importance of displacements, frequency changes, and Duschinsky rotations. In addition, we analyze the effect of different broadening functions (Gaussian, Lorentzian, or Voigt). Moreover, to assess the qualitative influence of anharmonicity on the internal conversion rate, we develop a simplified anharmonic model. We address the reliability of these models considering the potential errors introduced by the harmonic approximation and the phenomenological width of the broadening function.}, keywords = {}, pubstate = {published}, tppubtype = {article} } For the rational design of new fluorophores, reliable predictions of fluorescence quantum yields from first principles would be of great help. However, efficient computational approaches for predicting transition rates usually assume that the vibrational structure is harmonic. While the harmonic approximation has been used successfully to predict vibrationally resolved spectra and radiative rates, its reliability for non- radiative rates is much more questionable. Since non-adiabatic transitions convert large amounts of electronic energy into vibrational energy, the highly excited final vibrational states deviate greatly from harmonic oscillator eigenfunctions. We employ a time-dependent formalism to compute radiative and non-radiative rates for transitions and study the dependence on model parameters. For several coumarin dyes, we compare different adiabatic and vertical harmonic models (AS, ASF, AH, VG, VGF, and VH), in order to dissect the importance of displacements, frequency changes, and Duschinsky rotations. In addition, we analyze the effect of different broadening functions (Gaussian, Lorentzian, or Voigt). Moreover, to assess the qualitative influence of anharmonicity on the internal conversion rate, we develop a simplified anharmonic model. We address the reliability of these models considering the potential errors introduced by the harmonic approximation and the phenomenological width of the broadening function. |
4. | Hoche, Joscha; Schulz, Alexander; Dietrich, Lysanne Monika; Humeniuk, Alexander; Stolte, Matthias; Schmidt, David; Brixner, Tobias; Würthner, Frank; Mitric, Roland The origin of the solvent dependence of fluorescence quantum yields in dipolar merocyanine dyes Journal Article Chem. Sci., 10 , pp. 11013-11022, 2019. @article{hoche19b, title = {The origin of the solvent dependence of fluorescence quantum yields in dipolar merocyanine dyes}, author = {Joscha Hoche and Alexander Schulz and Lysanne Monika Dietrich and Alexander Humeniuk and Matthias Stolte and David Schmidt and Tobias Brixner and Frank Würthner and Roland Mitric}, url = {https://pubs.rsc.org/en/content/articlepdf/2019/sc/c9sc05012d}, doi = {10.1039/c9sc05012d}, year = {2019}, date = {2019-12-04}, journal = {Chem. Sci.}, volume = {10}, pages = {11013-11022}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
3. | Auerhammer, N; Schulz, A; Schmiedel, A; Holzapfel, M; Hoche, J; Röhr, M I S; Lambert, C; Mitric, R Dynamic exciton localisation in a pyrene-BODIPY-pyrene dye conjugate Journal Article Phys. Chem. Chem. Phys., 21 , pp. 9013-9025, 2019. @article{pccpbodipy, title = {Dynamic exciton localisation in a pyrene-BODIPY-pyrene dye conjugate}, author = {N. Auerhammer and A. Schulz and A. Schmiedel and M. Holzapfel and J. Hoche and M. I. S. Röhr and C. Lambert and R. Mitric}, url = {https://pubs.rsc.org/en/content/articlelanding/2019/cp/c9cp00908f#!divAbstract}, year = {2019}, date = {2019-03-21}, journal = {Phys. Chem. Chem. Phys.}, volume = {21}, pages = {9013-9025}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2. | Röhr, M I S; Marciniak, H; Hoche, J; Schreck, M; Ceymann, H; Mitric, R; Lambert, C Exciton Dynamics from Strong to Weak Coupling Limit Illustrated on a Series of Squaraine Dimers Journal Article J. Phys. Chem. C, 122 , pp. 8082–8093, 2018. @article{Röhr2018a, title = {Exciton Dynamics from Strong to Weak Coupling Limit Illustrated on a Series of Squaraine Dimers}, author = {M I S Röhr and H Marciniak and J Hoche and M Schreck and H Ceymann and R Mitric and C Lambert}, url = {https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.8b00847?journalCode=jpccck}, doi = {10.1021/acs.jpcc.8b00847}, year = {2018}, date = {2018-04-04}, journal = {J. Phys. Chem. C}, volume = {122}, pages = {8082–8093}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
1. | Hoche, J; Schmitt, H -C; Humeniuk, A; Fischer, I; Mitric, R; Röhr, M I S The mechanism of excimer formation: an experimental and theoretical study on the pyrene dimer Journal Article Phys. Chem. Chem. Phys., 19 , pp. 25002-25015, 2017. @article{hoche2017, title = {The mechanism of excimer formation: an experimental and theoretical study on the pyrene dimer}, author = {J Hoche and H -C Schmitt and A Humeniuk and I Fischer and R Mitric and M I S Röhr}, url = {http://dx.doi.org/10.1039/C7CP03990E}, year = {2017}, date = {2017-08-30}, journal = {Phys. Chem. Chem. Phys.}, volume = {19}, pages = {25002-25015}, abstract = {The understanding of excimer formation in organic materials is of fundamental importance, since excimers profoundly influence their functional performance in applications such as light-harvesting, photovoltaics or organic electronics. We present a joint experimental and theoretical study of the ultrafast dynamics of excimer formation in the pyrene dimer in a supersonic jet, which is the archetype of an excimer forming system. We perform simulations of the nonadiabatic photodynamics in the frame of TDDFT that reveal two distinct excimer formation pathways in the gas-phase dimer. The first pathway involves local excited state relaxation close to the initial Franck–Condon geometry that is characterized by a strong excitation of the stacking coordinate exhibiting damped oscillations with a period of 350 fs that persist for several picoseconds. The second excimer forming pathway involves large amplitude oscillations along the parallel shift coordinate with a period of ≈900 fs that after intramolecular vibrational energy redistribution leads to the formation of a perfectly stacked dimer. The electronic relaxation within the excitonic manifold is mediated by the presence of intermolecular conical intersections formed between fully delocalized excitonic states. Such conical intersections may generally arise in stacked π-conjugated aggregates due to the interplay between the long-range and short-range electronic coupling. The simulations are supported by picosecond photoionization experiments in a supersonic jet that provide a time-constant for the excimer formation of around 6–7 ps, in good agreement with theory. Finally, in order to explore how the crystal environment influences the excimer formation dynamics we perform large scale QM/MM nonadiabatic dynamics simulations on a pyrene crystal in the framework of the long-range corrected tight-binding TDDFT. In contrast to the isolated dimer, the excimer formation in the crystal follows a single reaction pathway in which the initially excited parallel slip motion is strongly damped by the interaction with the surrounding molecules leading to the slow excimer stabilization on a picosecond time scale}, keywords = {}, pubstate = {published}, tppubtype = {article} } The understanding of excimer formation in organic materials is of fundamental importance, since excimers profoundly influence their functional performance in applications such as light-harvesting, photovoltaics or organic electronics. We present a joint experimental and theoretical study of the ultrafast dynamics of excimer formation in the pyrene dimer in a supersonic jet, which is the archetype of an excimer forming system. We perform simulations of the nonadiabatic photodynamics in the frame of TDDFT that reveal two distinct excimer formation pathways in the gas-phase dimer. The first pathway involves local excited state relaxation close to the initial Franck–Condon geometry that is characterized by a strong excitation of the stacking coordinate exhibiting damped oscillations with a period of 350 fs that persist for several picoseconds. The second excimer forming pathway involves large amplitude oscillations along the parallel shift coordinate with a period of ≈900 fs that after intramolecular vibrational energy redistribution leads to the formation of a perfectly stacked dimer. The electronic relaxation within the excitonic manifold is mediated by the presence of intermolecular conical intersections formed between fully delocalized excitonic states. Such conical intersections may generally arise in stacked π-conjugated aggregates due to the interplay between the long-range and short-range electronic coupling. The simulations are supported by picosecond photoionization experiments in a supersonic jet that provide a time-constant for the excimer formation of around 6–7 ps, in good agreement with theory. Finally, in order to explore how the crystal environment influences the excimer formation dynamics we perform large scale QM/MM nonadiabatic dynamics simulations on a pyrene crystal in the framework of the long-range corrected tight-binding TDDFT. In contrast to the isolated dimer, the excimer formation in the crystal follows a single reaction pathway in which the initially excited parallel slip motion is strongly damped by the interaction with the surrounding molecules leading to the slow excimer stabilization on a picosecond time scale |